Programs to alter voice recordings

Greetings everyone,
I am looking for software that can alter voice recordings so they can be used without the speaker being recognized by the listeners. Does such a program exist? Up until now I have used command line utilities like ffmpeg and it’s associated filters.

You could try using Audacity. Select your audio recording and then adjust for pitch and speed, for example.

Thank for this suggestion. I ended up writing a small app using ffmpeg and putting a user interface in front of that. I needed to process about 90 files, and so my app does that in bulk. If that sounds interesting to anyone else, you can let me know here and we will get in touch with each other